– Photos

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Here is an assortment of photos of my Wang 1220. You'll quickly learn that
I'm not a good photographer, but it will have to do for now.

On each small image below, click to get a higher resolution version.

A picture of the system in its home environment ... my office.

View of the sound shield. The plexiglass cover can be folded into three positions (completely covered, just the keys exposed, entire typewriter exposed). Also, the entire hood can be removed.

The sound hood originally came with a layer of sound absorbing foam. Over the past 35 years it had dried out and turned into very crumbly stuff, so I scraped it all off with a painter's knife.

The 1200/1220 have two cassette tape drives for storing letters, templates, and simple databases for filling out form letters.

These are the switches on the left side of the Selectric keyboard to help control the 1220 editing process.

There are more switches on the right side of the Selectric keyboard.

The machine has sheet metal panels on the back to protect the logic inside, but they have been removed for the photos. The bay on the right is mostly empty, but the bay on the left houses the power supply and all the intelligence. The column of 11 white chips most visible in the photo holds the microcode.

By removing a couple hex nuts, the logic boards can swing out for access. Pulling on a couple knobs allows the ROM board to hinge out as well. This allowed easy service access while the machine was still operating.

Again, the logic cards are swung open. This shot is from the rear, showing the back of the motherboard and the back of the MOS ROM board. You'll note the two large horizontal bus bars for distributing power across the backplane. You can also make out a couple twisted pairs and some assorted other patch wires.

A thick cable of wires runs between the Selectric and the 1220 logic cards.

Although an earlier version used core ROM, this one uses mask programmed MOS ROM, a total of 2Kx44. At the top of the photo there is a diode matrix which can decode up to three address locations, and along side the ROMs, to the left, is three words of discrete diode ROM. These are used for patching the ROM, which gives some sense of how expensive it was to make new ROMs back in 1973.

Part of the linear power supply connection to the motherboard can be seen in this shot from the rear.

This is a close up of the logic boards. To the right you can make out the tops of the large electrolytic capacitors for filtering the output of the linear power supply.

The power regulation transistors are mounted on the frame, which also acts as a heat-sink.

The sticker reads: "DO NOT USE WIRED ROM". The earlier 1200 must have used ROM made of cores (see Wang 700).